Polyester blends comprising a desiccant and a rubbery block copolymer

ABSTRACT

Blends of a polyester with a desiccant and one or more of a poly(mono-1-olefin); a rubbery diene/monovinylarene block copolymer; or a poly(mono-1-olefin) and a rubbery block copolymer, optionally with a resinous poly(monovinylarene). Any of these blends can further employ an oil as an additional component.

FIELD OF THE INVENTION

The invention pertains to improved polyester blends. In another aspect,the invention pertains to blends of a polyester with a desiccant and oneor more of a poly(mono-1-olefin), a block copolymer ofdiene/monovinylarene, and a poly(monovinylarene). In another aspect, theinvention pertains to improved polyethylene terephthalate blends derivedfrom recycling of PET bottles.

BACKGROUND OF THE INVENTION

A major source of polyester, such as polyethylene terephthalate (PET),is the recycle of bottles made therefrom. These bottles conventionallyare prepared from a polyethylene terephthalate resin with a base overlaycup of high density polyethylene (HDPE) resin. Paper labels, etc. areutilized.

The usual separation plant, such as described in Modern Plastics, April,1980, page 82-3, crushes the received material, grinds it, and separatesfines and paper labels through such as fluidized-bed separationprocedures. The remaining materials primarily are polyethylene andpolyethylene terephthalate. Further separatory procedures are employedto obtain these two materials as separate streams for individual recycleand reuse.

Recently, a foamed polystyrene wrap-around label has been applied to thePET body. This presents an additional problem, now adding a third majordifferent polymer component to be separated.

Another problem experienced in the reuse of polyesters, whether obtainedfrom PET bottle recycling or other, has been the fact that thethermoplastic polyesters are subject to hydrolysis in the presence ofmoisture when in the molten state during (re)processing. This hydrolysisresults in a marked decrease in molecular weight, which then isreflected by marked lowering of physical properties, particularlytoughness. To prevent hydrolysis during (re)processing, it has beennecessary to dry the polyester to a moisture content of less than suchas about 0.005 weight percent or less, a difficult procedure withoutdeteriorating the polyester.

Needed are improved methods of reuse of the tremendous quantities of PETavailable in the form of recycle material. This material is either fromrecycle of the tremendous use of PET bottles, or from scrap in primarypolyester bottle forming and other purposes. Just for example, the abovereferred to Modern Plastics article indicated an estimated 1.5 billionPET soft-drink bottles shipped during 1979, accounting for anapproximate total of 150,000 metric tons of resin in that single usage.In the intervening time, this likely has doubled; presenting a largepotential area for useful recycle. Additionally, probably equivalentquantities of PET are used elsewhere in many other applicationspresenting equivalent opportunities for recycle.

BRIEF SUMMARY OF THE INVENTION

I have solved many of the problems in reusing polyesters. My inventionis based on a blend of (a) a polyester and (c) a desiccant.

(A) By blending (a) the polyester with (b) a block copolymer of aconjugated diene with a monovinylarene, and (c) a desiccant selectedfrom calcium, magnesium, strontium, barium, or aluminum oxides, I amable to produce a tough pliable product without the necessity of anydrying, retaining essentially the effective properties of the polyester.

(B) In a further aspect of my invention, I blend (a) polyester, (b) theaforesaid block copolymer of a conjugated diene with a monovinylarene,(c) the aforesaid desiccant, further with (d) a poly(mono-olefin) suchas high density polyethylene. This produces a tough, pliable product,with useful impact strength and elongation for injection molding, wellsuited as a substitute for impact polystyrene, for example.

(C) In another embodiment of my invention, I blend (a) polyester, (b)the block copolymer of a conjugated diene with a monovinylarene, (c) thedesiccant, (d) the polymono-1-olefin, preferably high densitypolyethylene, and (e) a polymonovinylarene, preferably polystyrene. Inaccordance with this aspect of my invention, the product is a tough,pliable product, suitable for molding of high impact parts. The productcan be prepared from blending, such as by grinding together, a PETbottle including the base cup and polystyrene label, supplementing withsuch added components as necessary for a balanced product, and includingmy important additive the conjugated diene/monovinylarene blockcopolymer.

(D) In a further embodiment of my invention, I blend (a) the polyester,(d) the poly(mono-1-olefin), and the (c) desiccant.

In related aspects of any of the above, I further use (f) an oil,preferably a light mineral process oil.

DETAILED DESCRIPTION OF THE INVENTION (a) Polyester

The (a) component is any of the polyesters known as polyester resins.These are described in detail in such as the Condensed ChemicalDictionary, 7th Edition, by Rose and Rose, pages 758-759 (Reinhold,N.Y., 1966). These polyesters also are described in such as BlockCopolymers by Allport and Janes (John Wiley, 1973) pages 264 andfollowing. Polyesters are prepared by esterification procedures,alcoholysis, acidolysis, ester-ester interchange, or reaction of acidchloride with alcohol, as described in many publications. Primarypreparation commercially, of course, is by esterification, reaction of apolyol with a polyacid. Most important of the polyester resins are thosedesignated as the polyalkylene terephthalates.

Particular types include such as polyethylene terephthalate,polypropylene terephthalate, polybutadiene terephthalate, and variousblends of the polyalkylene terephthalates or reaction products of amixture of reactants. Most important commercially at present are thepolyethylene terephthalate (PET), having a density of the order of about1.34 to 1.39 g/cc, commonly employed in the PET beverage bottles.

(b) Conjugated Diene Monovinylarene Block Copolymers

The (b) component is a block copolymer of a conjugated diene with amonovinylarene, with a sufficient balance of conjugateddiene:monovinylarene to be designated as a thermoplastic of rubbery(elastomeric) character. These block copolymers can be depicted by theformula (AB)_(n) Y wherein A and B respectively represent segments orblocks of polymonovinylarene (polymonovinyl-substituted aromaticcompound), and polyconjugated diene, and wherein Y is a residue of apolyfunctional initiator or a polyfunctional coupling agent. The blockcopolymers can be prepared either by polymerization procedures effectiveto prepare a linear block structure, or by sequential polymerizationprocedures with coupling, all as is well known in the art.

Suitable conjugated dienes are the hydrocarbon conjugated dienes usedalone or in admixture, and containing of the order of 4 to 12 carbonatoms per molecule, more usually 4 to 8 carbon atoms per molecule,including such as 1,3-butadiene and isoprene, both of these presentlybeing preferred, as well as such as 2,3-dimethyl-1,3-butadiene,piperylene, 3-butyl-1,3-octadiene, and the like.

Among the suitable monovinylarenes are those of 8 to 18 carbon atoms permolecule, such as the presently preferred styrene, as well as3-methylstyrene, 4-n-propylstyrene, 4-cyclohexylstyrene, 4-decylstyrene,2-ethyl-4-benzylstyrene, 4-p-tolylstyrene, the vinyl naphthalenes, andthe like, alone or in admixture.

Among the presently preferred block copolymers are such as thebutadiene/styrene block copolymers, in which the blocks can behomopolymeric, or tapered, isoprene/styrene block copolymers of similarnature, butadiene/styrene/vinyltoluene random block terpolymers, andother terpolymers such as the butadiene/styrene/alpha-methylstyreneblock terpolymers. Most preferably the block copolymer will have a ratioof about 50:50 conjugated diene:monovinylarene copolymerized weightratio to 75:25, presently preferred about 60:40.

(c) Desiccant

The (c) component is a desiccant capable of absorbing or reacting withwater, and as a desiccated component selected from the group consistingof calcium oxide, magnesium oxide, strontium oxide, barium oxide,aluminum oxide, partially hydrated aluminum oxide. Presently preferredis desiccated calcium oxide.

Presently preferred and available commercially is a commercial admixtureof either about 90 weight percent or 80 weight percent desiccatedcalcium oxide and correspondingly 10 or 20 weight percent of a lightmineral process oil employed both to provide a convenient means ofhandling the calcium oxide in effectively powdery, yet easily flowingform as well as a protection of the calcium oxide from absorbingmoisture, thus providing an easily dispersible form of the calcium oxidein polymers.

(d) Poly(mono-1-olefin)

The (d) component is a poly(mono-1-olefin), such as and presentlyparticularly preferred a high density or low density polyethylene, mostpreferably high density polyethylene. Other poly(mono-1-olefin)semployable are the normally solid polypropylene, polybutylene,polyisobutylene, poly(1-pentene), ethylene/butylene copolymers,ethylene/1-hexene copolymers, and various blends thereof.

It should be noted that the term "polyethylene" in the industry has cometo include a variety of copolymers in which several significant percentsof butylene, isobutylene, or 1-hexene, are included in the generalizedterm "polyethylene".

Presently most preferred because of its use as a protective lower cupexteriorly on PET bottles is a high density polyethylene, of a densityof about 0.93 to 0.97 g/cc.

(e) Poly(monovinylarene)

The (e) component is a poly(monovinylarene) (poly(monovinyl-substitutedaromatic compound)) based on hydrocarbon monovinylarenes. These arenormally solid, resinous materials, well known in the art. Presentlypreferred are the commercially available polystyrenes. Alternatively,useful and suitable materials include such as poly(alpha-methylstyrene),poly(vinyltoluene), and various blends thereof. Particularly usefulcommercial polystyrenes are those having a density of about 1.03 g/ccand a melt flow of such as about 2.5 g/10 min. However, any of thepoly(monovinylarenes) prepared from the monovinylarenes as detailedabove are usable. Many of the poly(monovinylarenes) may contain ascopolymerized components other ethylenically saturated compounds such asalpha-methylstyrene, acrylonitrile, methacrylates, and the like.

(f) Light Mineral Oil

The light mineral oil is an optional but desirable component in any ofmy blends. A suitable light mineral oil is described as a primarilyparaffic and naphthenic oil derived from crude oil, coal, oil shale andthe like, having an aromatic content of about 10 to 49 percent byweight, a specific gravity of about 0.85 to 0.95, a flash point of about300° F. to 600° F., and a viscosity at 100° F. of about 60 to 3500 SUS.

COMPOSITIONS

In my blends, any suitable and effective proportions can be used. Thepercentages given below are recommended for most purposes, but it shouldbe recognized that blends suitable for various applications can be madeoutside of the designated ranges.

It is recognized that the percentages in total may total greater thanone hundred percent, but since the composition is limited to 100percent, an increase in one component then is balanced by a decrease inone or more other components.

In my composition (A) of (a) polyester, (b) rubbery block copolymer, and(c) a desiccant, my inventive terblends are chosen in proportion so asto provide high impact strength, acceptable tensile properties, andhardness. Presently preferred are weight percentages of such as (a)about 50-90 weight percent polyester, more preferably about 70-85 weightpercent; (b) about 5 to 40 weight percent rubbery block copolymer, morepreferably about 10-20 weight percent; (c) about 3-20 weight percent ofthe designated desiccant, more preferably about 5-10 weight percent; andoptionally (f) about 0.5 to 5, preferably about 1-2, weight percent ofthe light mineral oil.

In the embodiment of my invention (B) employing the (a) polyester, the(b) rubbery block copolymer, (c) the desiccant, and (d) apoly(mono-1-olefin), the proportions preferably should be in the orderof (a) about 50-90 weight percent polyester, more preferably about 60-80weight percent; (b) about 3-30 weight percent of the rubbery blockcopolymer, more preferably about 10-20 weight percent; (c) about 3-20weight percent of the aforesaid desiccant, more preferably about 5-10weight percent; (d) about 3-25 weight percent of thepoly(mono-1-olefin), more preferably about 5-10 weight percent; and,optionally (f) the light mineral oil in the amount described above,about 0.5 to 5, preferably about 1-2, weight percent.

In the further embodiment (C) including (e) a polymonovinylarene,presently suggested weight percents are of the order of (a) about 25-75weight percent polyester, more preferably about 35-50 weight percent;(b) about 3-30 weight percent rubbery block copolymer, more preferablyabout 10-20 weight percent; (c) about 3-20 weight percent desiccant,more preferably about 10 to 20 weight percent; (d) about 10-35 weightpercent poly(mono-1-olefin), more preferably about 20 to 25 weightpercent, and (e) about 3-20 weight percent polymonovinylarene, morepreferably about 5-10 weight percent; and optionally (f) about 0.5 to 5,preferably about 1-2, weight percent of the light mineral oil.

In my blend embodiment (D) including (a) a polyester, (d) thepoly(mono-1-olefin), and (c) the dessicant, the presently suggestedweight percents are of the order of (a) about 50 to 90, more preferablyabout 80 to 90 weight percent: (d) about 3 to 20, more preferably about5 to 10 weight percent; and (c) about 3 to 20, more preferably about 5to 10 weight percent; and optionally (f) about 0.5 to 5, preferablyabout 1-2 weight percent.

BLENDING

My blends can be prepared, in any of the embodiments, by anyconventional and suitable means for combining such ingredients, such assolution blending, milling, batch mixing, continuous extrusion, and thelike.

The blends, of course, can contain conventional additives such asantioxidants, UV stabilizers, pigments, fillers, flame retardants, andthe like, as in known in the arts. The percentages of materials employedin the suggested and preferred blends are based on the weight of thetotal polymeric ingredients plus desiccant plus, where used, oil. Theseweights are exclusive of any of the other additives.

Preferably, my blends are prepared from recycled PET beverage bottles,and effectively eliminate the need for separating bottles, base cups,polystyrene labels, so-forth, before grinding. The blends can beprepared by dry blending, followed by subsequent extrusion at suitablemelt temperatures into strands, cooling, cutting into pellets, and thelike.

My blends can be molded by known molding processes, such as injectionmolding, into useful high impact resistant articles such as trays,containers, automotive parts, and the like.

Most usefully, when applied to the present PET composite bottles, Iproduce a useful product therefrom, and save considerable effort, work,and energy requirements otherwise presently consumed in present effortsto separate the individual components into individual recycle streamsfor individual applications.

EXAMPLES

Examples provided are intended to assist one skilled in the art to afurther understanding of the invention, and should be considered as suchand as a part of my overall disclosure. Particular components employedshould be considered as illustrative, and not limitative.

EXAMPLE I

In this example the preparation and properties of my inventive terblendscomprising polyester, a thermoplastic diene/monovinylarene copolymer,and a calcium oxide based desiccant are described.

The polyester used was a polyethylene terephthalate polymer regrind ofrecycled plastic beverage bottles and had a density of 1.34 to 1.39gm/cc. The block copolymer used was a preferred thermoplasticbutadiene/styrene copolymer Solprene® 414P, a 60:40 weight ratiobutadiene/styrene radial block copolymer, coupled with silicontetrachloride, having a melt flow at 200° C./5 kg of 5.0±1.0 g/10minutes (marketed by Phillips Chemical Co., a subsidary of PhillipsPetroleum Company). Solprene 414P contains about 0.5 weight percent ofBHT (2,6-di-t-butyl-p-cresol) and 0.5 weight percent of TNPP(tris[monotriphenyl]phosphite). The preferred desiccants used wereDesical Liquid, a commercial powdery mixture of 80 or 90 weight percentof calcium oxide and 10 or 20 weight percent of a light mineral processoil (marketed by Basic Chemicals, a division of Basic, Inc.) The mineraloil functions both to protect the calcium oxide from moisture and as aprocessing aid to incorporate the desiccant into the polymer blend.

My inventive terblends were prepared by dry-blending 10-lb batches in alarge Welex blender at a speed of 600-700 rpm, for 5-6 minutes. Blendcompositions are listed in Recipes IA and IB.

                                      Recipe IA                                   __________________________________________________________________________                  Run                                                                           1    2    3    4    5    6                                      Compound      Control                                                                            Invention                                                                          Invention                                                                          Control                                                                            Invention                                                                          Invention                              __________________________________________________________________________    PET (Regrind), parts by wt.                                                                 80   80   80   70   70   70                                     Solprene 414P, parts by wt.                                                                 20   20   20   30   30   30                                     Desical.sup.(a), parts by wt.                                                               --    5   10   --    5   10                                     __________________________________________________________________________     .sup.(a) Desical XL103, a powdery mixture of about 90 weight percent of       calcium oxide and about 10 weight percent of a light mineral process oil,     marketed by Basic Chemicals.                                             

                                      Recipe IB                                   __________________________________________________________________________                   Run                                                                           7    8    9     10    11    12                                 Compound       (Control)                                                                          (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                        __________________________________________________________________________    PET (Regrind), parts by wt.                                                                  100  100  85    80    75    70                                 Solprene 414P, parts by wt.                                                                  --   --   10    10    20    20                                 Desical Liquid.sup.(a), parts by wt.                                                         --   10    5    10     5    10                                 Weston, 618.sup.(b), parts by wt.                                                            --   --   0.5   0.5   0.5   0.5                                __________________________________________________________________________     .sup.(a) a powdery mixture of about 80 weight percent of calcium oxide in     about 20 weight percent of a light mineral process oil; marketed by Basic     Chemicals.                                                                    .sup.(b) distearylpentaerythritol phosphite, an antioxidant marketed by       Borg Warner Corp.                                                        

Subsequently, said blends were extruded in a NRM extruder (screwdiameter: 21/2 inches; L/d ratio 24:1), at a melt temperature of 505° F.and a screw speed of about 80 rpm. The extruded plastic strands werewater cooled and cut into pellets.

Test specimens were prepared by injection molding in a Reed-Prenticemolding apparatus at an average stock temperature during injection of500°-520° F. The mold temperature was kept at 50°-75° F.; cycle time was14 seconds per molded article.

Physical testing data of the 12 blends prepared in accordance withRecipes IA and IB are listed in Tables IA and IB.

                                      TABLE IA                                    __________________________________________________________________________                    Run                                                                           1.sup.(a)                                                                          2     3     4.sup.(a)                                                                          5     6                                                 (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Control)                                                                          (Invention)                                                                         (Invention)                       __________________________________________________________________________    Flexural Modulus.sup.(b), psi × 10.sup.-3                                               --   --    --    --   --    --                                Tensile Strength at Yield.sup.(c), psi                                                        --   5050  4930  --   3960  4180                              Elongation at Break.sup.(c), %                                                                --   42    17    --   21    45                                Shore D Hardness.sup.(d)                                                                      --   69    68    --   64    66                                Notched Izod Impact.sup.(e), ft lb/inch                                                       --   1.11  0.90  --   0.87  1.02                              Gardner Impact.sup.(f), inch-lb                                                               --   65    68    --   73    74                                Moisture Absorption.sup.(g), wt. %                                                            --    5     8    --    5     8                                __________________________________________________________________________

                                      TABLE IB                                    __________________________________________________________________________                      7    8    9     10    11    12                                                (Control)                                                                          (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                     __________________________________________________________________________    Flexural Modulus.sup.(b), psi × 10.sup.-3                                                 --   --   261   256   192   196                             Tensile Strength at Yield.sup.(c), psi                                                          6380 8640 6360  5930  4310  4260                            Elongation at Break.sup.(c), %                                                                   4    8   16    34    24    20                              Shore D Hardness.sup.(d)                                                                        78   77   79    77    74    73                              Notched Izod Impact.sup.(e), ft × lb/inch                                                 0.62 0.46 0.92  1.06  0.76  1.22                            Gardner Impact.sup.(f), inch-lb                                                                  6    8   75    86    131   115                             __________________________________________________________________________     Footnotes to Tables IA and IB                                                 .sup.(a) too brittle to test                                                  .sup.(b) determined according to ASTM D790                                    .sup.(c) determined according to ASTM D638                                    .sup.(d) determined according to ASTM D2240                                   .sup.(e) determined according to ASTM D256; thickness of specimen: 1/4        inch                                                                          .sup.(f) determined according to Instructional Manual of Gardner              Laboratories, IG1120, employing a 3/8 inch punch and a 4 lb weight            .sup.(g) after three weeks at 80 degrees F., relative humidity of 40%    

Data in Table IA show that the brittle and essentially useless blends ofpolyphenylene terephthalate and Solprene 414P copolymer (Runs 1 and 4)can be converted into blends having excellent impact resistance, highhardness, and good tensile properties (Runs 2, 3, 5, 6).

Data in Table IB show that the impact resistance and elongation of ablend comprising polyethylene terephthalate and a calcium oxidedesiccant (Run 8) can be drastically improved by the incorporation ofSolprene 414P butadiene/styrene radial block copolymer. The effect ofminute quantities of Weston 618 antioxidant upon physical properties ofthe prepared blends is believed to be negligible.

Data in Tables IA and IB clearly demonstrate that the addition of both athermoplastic butadiene/styrene radial block copolymer and a calciumoxide desiccant to polyethylene terephthalate is required to obtainblends with desirable combinations of high impact resistance, goodtensile properties, and high hardness. These blends are suitable formaking useful molded articles, such as trays, containers, automotiveparts, etc. Since my useful inventive terblends can be prepared fromground, recycled polyethylene terephthalate beverages bottles, practiceof my invention is valuable in that it contributes to the improvement ofthe environment and to the conservation of raw materials.

EXAMPLE II

In this example, the preparation and properties of another set ofinventive terblends are described. These terblends comprisedpolyethylene terephthalate, a high density polyethylene (Marlex 6006,density 0.963 g/cc; flow index CIL test procedure, 190° C., 1500 psinitrogen pressure 3.5 g/10 minutes, marketed by Phillips Chemical Co., asubsidiary of Phillips Petroleum Co.) and a desiccant (Desical Liquid,described in Example 1).

These terblends were blended, melt-extruded and injection molded inaccordance with the procedures described in Example I. Representativeruns were prepared in accordance with Recipe II.

                                      Recipe II                                   __________________________________________________________________________                   Run                                                                           8    13    14    15    16                                      Compound       (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                             __________________________________________________________________________    PET (Regrind).sup.(a), parts by wt.                                                          100  90    85    85    80                                      Polyethylene.sup.(b), parts by wt.                                                           --   5     10     5    10                                      Desical Liquid.sup.(a), parts by wt.                                                         10   5      5    10    10                                      Weston, 618.sup.(c), parts by wt.                                                            --   0.5   0.5   0.5   0.5                                     __________________________________________________________________________     .sup.(a) see Example I                                                        .sup.(b) Marlex 6006 highdensity polyethylene; density: 0.936 g/cc            .sup.(c) see Footnote to Recipe IB                                       

Physical properties of these runs are summarized in Table II.

                                      TABLE II                                    __________________________________________________________________________                      Run                                                                           8    13    14    15    16                                                     (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                          __________________________________________________________________________    Flexural Modulus.sup.(b), psi × 1.sup.-3                                                  --   301   264   295   266                                  Tensile Strength at Yield.sup.(a), psi                                                          8640 7840  7090  6980  6410                                 Elongation at Break.sup.(a), %                                                                   8   47    11    27    26                                   Shore D Hardness.sup.(a)                                                                        77   79    77    79    76                                   Notched Izod Impact, ft × lb/inch                                                         0.46 1.38  1.45  1.60  1.59                                 Gardner Impact.sup.(a), inch-lb                                                                  8   53    54    76    78                                   __________________________________________________________________________     .sup.(a) see Footnotes to Table IA and IB                                

Data in Table II show that my inventive terblends comprising apolyethylene terephthalate, high density polyethylene, and a calciumoxide desiccant (Runs 13-16) have excellent impact, tensile and hardnessproperties. These terblends could be prepared by grinding plasticbeverage bottles without separating the PET bottle and the PE base cup.The presence of the calcium oxide based desiccant will protect thepolyethylene terephthalate from hydrolytic degradation during aging inthe presence of humid air.

EXAMPLE III

Inventive, four-component blends comprising polyethylene terephthalate,high-density polyethylene, a thermoplastic butadiene/styrene blockcopolymer, and a calcium oxide based desiccant, were prepared inaccordance with the procedure outlined in Example I. Blend compositionsare given in Recipe III.

                                      Recipe III                                  __________________________________________________________________________                   Run                                                                           8    17    18    19    20    21    22                          Compound       (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                 __________________________________________________________________________    PET (Regrind).sup.(a), parts by wt.                                                          100  80    75    75    70    65    60                          Solprene 414P.sup.(a), parts by wt.                                                          --   10    10    10    10    20    20                          Marlex HDPE.sup.(b), parts by wt.                                                            --    5    10     5    10     5    10                          Desical Liquid.sup.(c), parts by wt.                                                         10    5     5    10    10    10    10                          Weston, 618.sup.(c), parts by wt.                                                            --   0.5   0.5   0.5   0.5   0.5   0.5                         __________________________________________________________________________     .sup.(a) see Example I                                                        .sup.(b) see Footnote to Recipe II                                            .sup.(c) see Footnote to Recipe IB                                       

Physical test data for my inventive four-component blends are summarizedin Table III.

                                      TABLE III                                   __________________________________________________________________________                     Run                                                                           8    17    18    19    20    21    22                                         (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)               __________________________________________________________________________    Flexural Modulus.sup.(a), psi × 10.sup.-3                                                --   234   220   226   211   177   161                       Tensile Strength at Yield.sup.(a), psi                                                         8640 5410  5130  5270  4900  4040  3560                      Elongation at Break.sup.(a), %                                                                  8   12    13    11    12     8     8                        Shore D Hardness.sup.(a)                                                                       77   75    73    74    74    70    70                        Notched Izod Impact.sup.(a), ft × lb/in                                                  0.46 0.87  0.85  0.81  0.76  0.58  0.55                      Gardner Impact.sup.(a), inch-lb                                                                 8   44    45    33    36    49    47                        __________________________________________________________________________     .sup.(a) see Footnotes to Table IA and IB                                

These data show that the inventive blends (Runs 17-22) have superiorimpact properties versus a control blend comprising PET plus Desical(Run 8). Tensile properties and hardness, however, are lower than thoseof control Run 8. The inventive four-component blends of Runs 17-22 areless preferred than other inventive blends described in Examples I andII, but they are superior to all control blends (Runs 1, 4, 7, and 8).

EXAMPLE IV

Another embodiment of my invention is a five-component blend comprisingpolyethylene terphthalate, a thermoplastic butadiene/styrene blockcopolymer (preferably Solprene 414P), a high density polyethylene(preferably Marlex 6006), a calcium oxide desiccant (preferably DesicalLiquid), and, a polystyrene resin (preferably Cosden 550, marketed byCosden Oil Company; melt flow: 2.5 g/10 minutes, determined at 200° C./5kg, according to ASTM D1238 condition G; Vicat temperature of 220° F.,according to ASTM 1525-70; density approximately 1.03 g/cc).

My inventive five-component blends were prepared by dry-blending 10-lbbatches in a Welex blender, extruding the polymer at a melt temperatureof 505° F. in an NRM melt-extruder and cutting the extruded,water-cooled polymer strands into pellets. Test specimens were preparedby injection molding at about 500° F. in an Arburg molding apparatus.Said molding was done at a fast cycle (approximately 20 seconds) whilethe mold was kept cold.

Blend compositions are given in Recipe IV.

                                      Recipe IV                                   __________________________________________________________________________                   Run                                                                           23   24    25    26    27                                      Compound       (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                             __________________________________________________________________________    PET (Regrind).sup.(a), parts by wt.                                                          90   50    45    40    35                                      Desical Liquid.sup.(a), parts by wt.                                                         10   10    10    10    10                                      Solprene 414P.sup.(a), parts by wt.                                                          --   10    10    20    20                                      Polyethylene.sup.(b), parts by wt.                                                           --   25    25    25    25                                      Polystyrene.sup.(c), parts by wt.                                                            --    5    10     5    10                                      __________________________________________________________________________     .sup.(a) see Footnote to Recipe IB                                            .sup.(b) see Footnote to Recipe II                                            .sup.(c) Cosden 550, density: about 1.03 g/cc; melt flow: 2.5 g/10 min.  

Physical properties are listed in Table IV.

                                      TABLE IV                                    __________________________________________________________________________                      Run                                                                           23   24    25    26    27                                                     (Control)                                                                          (Invention)                                                                         (Invention)                                                                         (Invention)                                                                         (Invention)                          __________________________________________________________________________    Flexural Modulus.sup.(a), psi × 10.sup.-3                                                 323  176   177   130   127                                  Tensile Strength at Yield.sup.(a), psi                                                          6240 4040  4100  3060  2920                                 Elongation at Break.sup.(a), %                                                                   9   20    14    17    35                                   Shore D Hardness.sup.(a)                                                                        66   60    62    66    60                                   Heat Distortion at 66 psi.sup.(b), degrees F.                                                   181  178   182   177   178                                  Notched Izod Impact.sup.(a), ft × lb/inch                                                 0.99 0.79  0.72  0.93  0.90                                 Gardner Impact.sup.(a), inch-lb                                                                 23   66    24    64    81                                   __________________________________________________________________________     .sup.(a) see Footnotes to Tables IA and IB                                    hu (b)Determined according to ASTM D1637                                 

My inventive five-component blends have higher Gardner impact resistanceand higher elongation than a control blend (Run 23). Tensile properties,flexural moduli, and notched Izod impact are generally lower for myinventive blends. My inventive five-component blends could becommercially prepared by grinding plastic beverage bottles withoutseparating the polyethylene bottle parts, polyethylene base cups, andpolystyrene wrap-around labels, and subsequently adding a thermoplasticbutadiene/styrene copolymer and a suitable desiccant (for instance,Desical Liquid).

The disclosure, including data, has illustrated the value andeffectiveness of my invention. The examples, the knowledge andbackground of the field of the invention and the general principles ofchemistry and of other applicable sciences have formed the bases fromwhich the broad descriptions of my invention including the ranges ofconditions and the generic groups of operant components have beendeveloped, and formed the bases for my claims here appended.

I claim:
 1. The polyester composition consisting essentially of(a) about50 to 90 weight percent polyalkylene terephthalate polyester, (b)rubbery block copolymer, and (c) desiccant, wherein said desiccant isselected from the group consisting of calcium oxide, magnesium oxide,strontium oxide, barium oxide, and aluminum oxide;optionally furtherwith (f) light mineral oil.
 2. The polyester composition consistingessentially of(a) about 50 to 90 weight percent polyalkyleneterephthalate polyester, (b) rubbery block copolymer, (c) desiccant,wherein said desiccant is selected from the group consisting of calciumoxide, magnesium oxide, strontium oxide, barium oxide, and aluminumoxide; and (d) poly(mono-1-olefin);optionally further with (f) lightmineral oil.
 3. The polyester composition consisting essentially of(a)about 25 to 75 weight percent polyalkylene terephthalate polyester, (b)rubbery block copolymer (c) desiccant, wherein said desiccant isselected from the group consisting of calcium oxide, magnesium oxide,strontium oxide, barium oxide, and aluminum oxide; (d)poly(mono-1-olefin), and (e) poly(monovinylarene);optionally furtherwith (f) light mineral oil.
 4. The composition according to claim 1, 2,or 3 further including said (f) light mineral oil.
 5. The composition ofclaim 1 employing about 5 to 40 weight percent (b), and about 3 to 20weight percent (c); and where present about 0.5 to 5 weight percent (f).6. The composition of claim 5 employing about 70-85 weight percent (a),about 10-20 weight percent (b), and about 5-10 weight percent (c); andwhere present about 1-2 weight percent (f).
 7. The composition of claim2 employing (a), about 3 to 30 weight percent (b), about 3 to 20 weightpercent (c), and about 3 to 25 weight percent (d); and where presentabout 0.5 to 5 weight percent (f).
 8. The composition of claim 7employing about 60 to 80 weight percent (a), about 10 to 20 weightpercent (b), about 5 to 10 weight percent (c), and about 5 to 10 percent(d); and where present about 1 to 2 weight percent (f).
 9. Thecomposition of claim 3 employing (a), about 3 to 30 weight percent (b),about 3 to 30 weight percent (c), about 10 to 35 weight percent (d), andabout 3 to 30 weight percent (e); and where included about 0.5 to 5weight percent (f).
 10. The composition of claim 9 employing about 35 to50 weight percent (a), about 10 to 20 weight percent (b), about 10 to 20weight percent (c), about 20 to 25 weight percent (d), and about 5 to 10weight percent (e); and where employed about 1 to 2 weight percent (f).11. The composition of claim 1, 2, 3, 5, 6, 7, 8, 9, or 10 wherein said(a) is polyethylene terephthalate, and said (c) desiccant is a calciumoxide.
 12. The composition of claim 1, 2, 3, 5, 6, 7, 8, 9, or 10,wherein said (b) is a butadiene/styrene block copolymer, said (a) ispolyethylene terephthalate, and said (c) is a calcium oxide.
 13. Thecomposition of claim 2, 3, 7, 8, 9, or 10, wherein said (a) ispolyethylene terephthalate, said (d) is a polyethylene, and said (c) isa calcium oxide.
 14. The composition of claim 2, 3, 7, 8, 9, or 10wherein said (a) is polyethylene terephthalate, said (b) is abutadiene/styrene block copolymer, said (d) is a polyethylene, and said(c) is a calcium oxide.
 15. The composition of claim 3, 9, or 10,wherein said (a) is a polyethylene terephthalate, said (b) is abutadiene/styrene block copolymer, said (c) is a calcium oxide, said (d)is a polyethylene, and said (e) is a polystyrene.
 16. The composition ofany of claims 5, 6, 7, 8, 9, or 10, wherein said (a) is a PET bottleregrind.
 17. A polyester blend composition consisting of:(a) about 50 to90 weight percent polyalkylene terephthalate, (b) about 5 to 40 weightpercent rubbery block copolymer of a hydrocarbon conjugated diene with amonovinylarene, and (c) about 3 to 20 weight percent of a desiccantselected from the group consisting of calcium oxide, magnesium oxide,strontium oxide, barium oxide, and aluminum oxide; and optionally (f)about 0.5 to 5 weight percent of light mineral oil.
 18. A polyesterblend composition consisting of:(a) about 50 to 90 weight percentpolyalkylene terephthalate, (b) about 3 to 30 weight percent of arubbery block copolymer of a hydrocarbon conjugated diene with amonovinylarene, (c) about 3 to 20 weight percent of a desiccant selectedfrom the group consisting of calcium oxide, magnesium oxide, strontiumoxide, barium oxide, and aluminum oxide, and (d) about 3 to 25 weightpercent of a poly(mono-1-olefin); and optionally (f) about 0.5 to 5weight percent of light mineral oil.
 19. A polyester blend compositionconsisting of:(a) about 25 to 75 weight percent polyalkyleneterephthalate, (b) about 3 to 30 weight percent of a rubbery blockcopolymer of a hydrocarbon conjugated diene with a monovinylarene, (c)about 3 to 20 weight percent desiccant selected from the groupconsisting of calcium oxide, magnesium oxide, strontium oxide, bariumoxide, and aluminum oxide, (d) about 10 to 35 weight percent of apoly(mono-1-olefin), and (e) about 3 to 20 weight percent of apolymonovinylarene; and optionally (f) about 0.5 to 5 weight percent oflight mineral oil.